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Where did you get your brains? – Baby mice may inherit their mother’s wits and their father’s basicinstincts, but what does this mean for us, asks Gail Vines

By Gail Vines

“WE could produce remarkable children,” a beautiful actress once cooed to the cerebral Irish playwright George Bernard Shaw. “Ah yes,” he replied, quick as a flash, “but what if they had my looks and your brains?”

A simple joke about vanity and the vagaries of sexual reproduction, perhaps. But Shaw’s quip may be more apt than he could ever have guessed. Pioneering work on mice suggests that a mother’s genes play the dominant role in the development of the parts of her offsprings’ brains that are responsible for intelligence. The father’s genes, on the other hand, may shape not his offsprings’ looks so much as the parts of their brains that influence emotional make-up. Safe to say, it won’t just be the textbooks that suffer a major shake-up if the astonishing new findings hold true for humans.

Women seeking intelligent children might decide that a trip to the Nobel prizewinners’ sperm bank is a waste of time, and instead choose easy-going husbands over intellectual high-flyers. Men interested in the IQ of their offspring might suddenly find smart wives more appealing. Eugenics could resurface in a new guise as repressive regimes allow only brainy women to have babies.

The strange genes that threaten even greater social ferment than cloning are “imprinted” genes. Genes exist in pairs, one from the mother and one from the father. Most of the time one can’t be told from the other-the two are equally active. But imprinted genes are different. They carry a biochemical label that reveals their parental origin and determines whether or not they are active inside the cells of the …